React Js Interview Questions

General
1
  1. What is hoisting in UseState?
  2. How does it work?
  3. What is the difference between let and var?
  4. What is the Event Loop?
  5. What is precedence in the Event Loop?
  6. What is the difference between setTimeout and setInterval?
  7. Where do you use the Rest Operator?
  8. Have you heard of array.reverse?
  9. What is meant by Shallow copy and Deep copy?
  10. What are Closures?
  11. Have you used the reduce function in JS?
  12. What is the difference between map and reduce?
  13. What parameters does the map function accept?
  14. What is the difference between a Promise and a Callback?
  15. What position attributes in CSS have you used?
  16. What is the difference between them?
  17. What is Flexbox?
  18. What is the difference between display=none and visibility=hidden?
  19. What Hooks have you used?
  20. What is the purpose of useCallback?
  21. What are Class-based Lifecycle methods?
  22. How can you achieve componentDidMount, componentDidUpdate & componentDidUnMount in a functional-based component?
  23. What are Pure Components and their purpose?
  24. What are Higher Order components?
  25. What HOCs have you used?
  26. Have you used the Context API?
  27. You already have state management in React, so why go for Redux?
  28. How does Redux work?
  29. Have you used any Middlewares?
  30. What is the purpose of using middlewares?